strange U bolt question
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Senior User
Joined: Sep 2004
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strange U bolt question
Ok, I was recently pulling my stock 2" blocks off the rear axle to put some 3" ones in it's place....... I know..... long story.
Anyway, the new u bolts didn't fit exactly over the axle. I mean they fit but wer rounded a little short, so I had to tap the bottom of em with a hammer. Well that widened them at the top where they go through the plate. I pulled them together with a pair of channel locks and threw the nuts on em. Now when I went to torqe them down, 75ft lbs according to my crafstman tq wrench, the felt incredibly tight then loose. I am assuming it was due to the bolt streching to the right shape. Well sure enough, one of the nuts stripped the bolt and popped. Now these are grade 8 gold bolts. Is this normal, or are they just junk. I am thinging about ordering some more from bronograveyard, but they look like the same damm ones.
Anyone experienced this?
Chris
Anyway, the new u bolts didn't fit exactly over the axle. I mean they fit but wer rounded a little short, so I had to tap the bottom of em with a hammer. Well that widened them at the top where they go through the plate. I pulled them together with a pair of channel locks and threw the nuts on em. Now when I went to torqe them down, 75ft lbs according to my crafstman tq wrench, the felt incredibly tight then loose. I am assuming it was due to the bolt streching to the right shape. Well sure enough, one of the nuts stripped the bolt and popped. Now these are grade 8 gold bolts. Is this normal, or are they just junk. I am thinging about ordering some more from bronograveyard, but they look like the same damm ones.
Anyone experienced this?
Chris
More Turbo
Joined: Mar 2008
Posts: 658
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Sounds like you torqued them too much and they stripped out? Did you find out if the bolt or the nut stripped? I would assume it was the bolt.
If they are grade 8 and you are stripping them out, you are applying too much torque for that bolt, methinks...
With u-bolts you sorta have to do one side, then the other, and so on, so they seat evenly and don't get jacked up.
With mine I just torqued it down with the impact wrench for a second or so, checked it in a week and it was fine...
If they are grade 8 and you are stripping them out, you are applying too much torque for that bolt, methinks...
With u-bolts you sorta have to do one side, then the other, and so on, so they seat evenly and don't get jacked up.
With mine I just torqued it down with the impact wrench for a second or so, checked it in a week and it was fine...
Hotshot
Joined: Sep 2001
Posts: 11,958
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Also, when tightening them up do so in a diagonal pattern. Don't just tighten up one nut at a time. You'll have to go aroung the 4 nuts several times. You want the amount of exposed threads to be close to the same. I think leaf spring to rear axle U bolts are supposed to be torqued to 80-100 lbs. Some one correct me if I am wrong.
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Senior User
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they are goldish in color, and since grade 8 bolts are the same color I assumed they were the same. I'll call a machine shop, and possibly the ol ford dealership and see if they have exteneded u bolts.
Thanks
Chris
Thanks
Chris
Fleet Mechanic
Joined: Nov 2003
Posts: 1,372
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From: West Cornwall, CT
As Conanski mentioned, there is no way you could strip grade 8 fasteners with normal hand tools. Those gold colored U-bolts were just cadmium plated lower grade material. Since you had a problem with fit, they were probably too narrow to fit your axle. New U-bolts should fit perfectly.
The last time I needed U-bolts I used Skyjacker parts. They were cadmium plated and fit fine. The touque value was somewhere around 150 ft-lbs. 75 sounds a bit low.
Lou Braun
The last time I needed U-bolts I used Skyjacker parts. They were cadmium plated and fit fine. The touque value was somewhere around 150 ft-lbs. 75 sounds a bit low.
Lou Braun
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Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 12
From: Sand Lake, MI
I buy my u bolts at a spring shop, a shop that specializes in large tractor trailer spring/axles.
I tell them the leg length, the leg diameter, round or square and the axle diameter for the bolts I want.
They pull the appropriate length and diameter stock off the rack, put the appropriate die's that match my measurements in the press and bend em while I watch.
Then give em to me with the nuts that go with them, not your average hardware store nut either. Nuts are usually 3/4" to over a 1" tall, plenty of "fine" thread to grab the legs with.
The prices at the spring shop are much better then the auto parts and the quality is definitely worth the extra trip.
They should be tighten then put in service for 100 miles or so, and then re tightened.
I have never stripped one, I use a half inch drive ratchet with the 4' long handle from my floor jack on it to draw them up tight. A u bolt will stretch a long ways before its tight.
A air gun will make it easy to take up all the slack to get everything in place nice yea, but one will not tighten them sufficiently by itself, like trying to tighten a spring.
I tell them the leg length, the leg diameter, round or square and the axle diameter for the bolts I want.
They pull the appropriate length and diameter stock off the rack, put the appropriate die's that match my measurements in the press and bend em while I watch.
Then give em to me with the nuts that go with them, not your average hardware store nut either. Nuts are usually 3/4" to over a 1" tall, plenty of "fine" thread to grab the legs with.
The prices at the spring shop are much better then the auto parts and the quality is definitely worth the extra trip.
They should be tighten then put in service for 100 miles or so, and then re tightened.
I have never stripped one, I use a half inch drive ratchet with the 4' long handle from my floor jack on it to draw them up tight. A u bolt will stretch a long ways before its tight.
A air gun will make it easy to take up all the slack to get everything in place nice yea, but one will not tighten them sufficiently by itself, like trying to tighten a spring.
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